Manufacture of motor fuel



Filed Aug. 15, i 1942 PIL? III

ROBERT THOMAS SANDERsoN /N VENTO/e A TT ORNE Y Patented July 23, 1946 t i l 1 MANUFACTURE oF Moron FUEL `Robert Thomas Sanderson, Beacon, N. Y., assignor to The Texas Company, New York, N. Y., a corporation of Delaware Application August 15, 1942, Serial No. 454,970 i Claims.

This invention relates to the manufacture of motor fuel and particularly to motor fuel rich.

in branched chain hydrocarbons.

The invention has to do With obtaining 2,2,3- trimethylbutane from a mixture comprising the treated hydrocarbon mixture.

octane value.

fractional distillation methods.

trimethylbutane and its isomer 2,4-dimetloyl` 5 organo metallic compounds. i y pentane by a process involving treating the mix- One procedure for the catalytic preparation of ture with sulfuric acid under conditions such 2,2,3-trimethylbutane involves reacting a methyl that 2,4-dimethylpentane undergoes conversion' aluminum halide with an alkyl halide as deinto 2,3-dimethy1pentane, and distilling a. frac- 10 scribed in my pending application, Serial No. tion rich in 2,2,3-trimethylbutane from the 452,698, iiled July 29, 1942, for improvements in Advantageously, Organic synthesis. I the treatment of the hydrocarbon mixture is ef- As therein disclosed methyl aluminum chlofected with concentrated sulfuric acid at a temride or other alkyl aluminum halide is placed perature in the range about 70 to 125 `F. The 15 or formed in a suitable reaction vessel, and an acid treated mixture is subsequently treated with aliphatic halide such as 2-chloro2,3dimethyl alkali prior to distillation for the purpose of butane is introduced slowly, advantageouslyV in removing traces of acid remaining in the hydrothe form of a solution in 2,3-dimethy1butane. carbons. i This solution containing about 12 to 15% of the The hydrocarbon 2,2,3-trimethylbutane boils chlorodimethylbutane is added over a period of at a temperature of about 178 F. while the about-,3 hours, while maintaining areaction temisomer 2,4-dimethylpentane boils at a temperaperature in the range about minus 58 to 32 F. ture of about 177 F. In the catalytic prepara- The total solution added amounts to about 15 to tion of 2,2,3-trimethylbutane relatively large 2o parts by weight per part of methyl aluminum amounts of the isomer may be present. The chloride. I isomer 2,4-dimethylpentane has a C. F. R. M. As previously intimated other methods of preoctane value of about 82 or thereabouts, whereas paring branched chain hydrocarbon mixtures 2,2,3-trimethylbutane has a materially higher containing 2,2,3-trimethylbutane and 2,4-di- For this reason it is frequently methylpentane may be employed. desirable to produce the trimethylbutane in as In any case, the synthetic hydrocarbon mixconcentrated form as possible for the purpose ture is subsequently treated with concentrated of making high octane motor fuel. Due to the acid and thereafter distilled in accordance with similarity in boiling temperatures, however, this the method of this invention so as to obtain a` separation cannot be effected by conventional hydrocarbon product rich in 2,2,3-trimethylbutane.

It has been found that concentrated sulfuric Reference will now be made to the accompanyacid at temperatures in the range about 70 toing drawing illustrating one method of iiow which 125 F. exerts no substantial effect upon 2,2,3- may be employed in practicing the invention. trimethylbutane, but under the same condii In the drawing methyl aluminum chloride from tions does effect substantial conversion of 2,4- a source not shown is introduced through a pipe dimethylpentane into 2,3-dimethylpentane which I to an alkylation unit 2. has a materially higher boiling point, namely, 2,3-dimethylbutane is introduced from a source about 194 F. Consequently, the acid treated not; shown through a pipe 3 to the unit 2. hydrocarbon mixture can be subjected to charge materials are thus subjected to reaction fractional distillation and thereby effect rein the unit 2 so as to produce a hydrocarbon prod. moval of the more volatile hydrocarbons from uct vcontaining 2,2,3-trimethylbutane and 2,4-dithe higher boiling and less valuable hydrocarbon. methylpentane.

For example, by subjecting 2,4-dimethylpentane The hydrocarbon mixture is accumulated in a to the action of H2504 at a temperature of tank 4 from which it may be conducted through about F. for a period of 2 hours some 15%` 5o a pipe 5 to a mixer B wherein it is brought into or more of the hydrocarbon is converted to 2,3- dimethylpentane. The acid treatment apparently causes isomerization of the afl-dimethylpentane. n

\ Mixtures of the trimethylbutane and its isomer Z 2,4-dimethylpentane may be obtained by various methods of organo metallic synthesis. They may be obtained in processes of isomerization and alkylation and by cross polymerization with subsequent hydrogenation and synthesis through A solution of 2-chloro- The contact with concentrated sulfuric acid introduced through a pipe 1. This acid may have a concentration of about 94% to 100% or more `of HzSO4, and preferably a concentration'of about 97% H2SO4.

The mixture of acid and hydrocarbons is subjected to thorough agitation in the mixer 6 While maintained at a temperature of about 7 0 to 125 F. over a period of about 20 minutes to 3 hours.

The products of reaction are drawn off through a pipe 8 to a settler 9 wherein separation into hydrocarbon and acid phases respectively occurs.

I3 wherein it may be treatedwith alkali for the purpose of removing remaining acid therefrom;

The 'neutralized hydrocarbons are then passed through a pipe' I4 to-afractionator l5. The frac,- tionator t5 is operated sozaszto separate from. the hydrocarbon mixture. a distillatev fraction. con'.- taining.Y 2',2,3-trimethylbutane and unreactedl 2,4 dmethylpenta'ne; charged from the fractionator. through a, pipe |162. The., residual fractionY removedl from: the. bottom on.' theifractiorrator through apipel1 comprises. 2-,3dimethylpentane.

The: distillate fraction removed through the; pipe I6: may still contain a relatively larga amount of 2,4-dimethylpentane. and further; conversion.` of this' material into the. higli'er` boiling 2`,'3rdmethy1pentane may; be effected by recycling to. the: mixer: l.4 Insteadi ofrecyc'lingto thev mixer 6-it i'sadvantageousto pass the hydrocarbon mixe turetoraseparate. stage. Thus; the hydrocarbons `are;` passedthrough'. the. pipe.- k6. to a1 second'.A 2Q' which' may b'e'simiiar' toi the: mixer A andU wherein. the; hydrocarbons; are; again brought into. contact witlrconcentrated; sulfuric: acid under` substantiall'yJ similar conditions so: as. to effect further conversion. of; the, ZA-dimethyipentane; into; 2,3;-dimethylpentane The reaction mixture is subsequently passed through a pipe, 2|v to a: settler 22 wherein the hydrocarbon' phaseI is separated from the. acid-Y phase.

The acid phasesisdrawn-l of. through a pipe.- 23' and; may bel discharged all' or: in part from the system. Advantageously, however, this acid is. conducted; through a pipe 241 communicating With the. previously mentioned pipe.` l; wherein.y itis.Y recycledtothe mixer Bfor the primary stage; In this type of operation fresh acid may be introducedtothe secondary stage through the pipe 25 Whilevused acidi removed fromthe secondarystage settler 22'A isused-.solely or largely as, the-re.` agent in the prima-rystage mixer 6.. In th'isway acountercurrent treatment betweenA acid and hy drocarbons is.- utilized. v

Where theV usedV acid is not so recycled; from the secondary stage or onlyy returned in part,. fresh acidfmay be passedv directly from. a pipe 26 totheprimary stage mixer 6.

The hydrocarbon phaseisf drawn 01T. fromf the settler 22 through a pipe 21 to a neutralizer'28- wherein the: remaining acid is removed'` from the hydrocarbons..

This distillate fraction isr dis'.-

pentane drawn oir from the fractionator 29 through a pipe 32 may be conducted together y with the hydrocarbon drawn off through the pipe l1 to a tank 33. Y

The liquid fraction comprising 2,3-dimethylpentane drawn 01T from .the fractionator 29 through a pipe 32 may be conducted together with the hydrocarbon drawnoi throughthe, pipe I1 to a tank 33.

The above described method of flow comprises a two-stage operation. However, it is contemplatedA that any number of stages Vmay be used or instead a single stage may be used as already' intimated. Moreover, the conditions of 1 acid treatment may'vary from stage to stage with respect to acid" concentration, temperature and time of contact.

Obviously many modifications and variations of the' invention, as hereinbefore set forth, may be made without departing from the spirit and scope. thereof', andi therefore only such limitations should: be: imposed: as arezindicatedi the'.i appended claims;

I'claim:

1. 'Ilrrev method ofev removing. 23s-dimethylpen..-x

` tane from. amixture: comprising 2.4idimethylpena The? neutralized hydrocarbons are thennpassedi 1 to: a. fractionator 29goperatedz irr aA similar? manner to thezfiactionator F55.

Thev distillate fraction riclr in 2;2,3trimethyl; butarre is-y drawnoi througnapipe 30mg; tank' 3.15.. The liquid fraction comprising l-dimethyl;

tane: and;r 21,2 3trimethylbutane,. which conrprises subjecting; said mixturetof theactionao' concert..-y tratedsulfurc acid ata .temperature in the range:l about 'Z0 to 125: F..for a period; ofy time lessi than. about 3; hours,r such" that. 2;,42-dimethylpentanec undergoessubstantial conversionl into12=,3 edimethzf: ylpentane: while 2,2-,`3;-trim'ethylbutane. remains; substantially unchanged. removing; acidv fromathe treated hydrocarbon.- mixture;V and ldistillingK a.

fraction enriched ilrl 2,2-3"trimethylbutane from the treated-g hydrocarbon, mixture, the: remaimng hydrocarbons comprising 2,3%-dimethylpentane..-V 2. In the manufacture of 2,2,3-trimethylbutane.. t-he steps: comprising.I forming au hydrocarbon mixture.: containing. 2 ;2;3.trimethylb11tanel and: its:l isomer ZA-dimethylpentane, treating the: hydro@V carbon. mix-ture'.r with, sulfuric' acid. atv a: tempera.- ture.l in the.- range ab'out;7S0-t'o;125 for aperiod: of: time. lessi than;`about 3 hours. such; that.' 2,45 dmethylpentane. undergoes substantial. com/.eir-4 sion'. int-o, 2,3.--dimethylpentanez while 2;2,3f.-t1:i: methylbutane: remains substantially unchanged.. removing acid from; the vtreated;hydrocarbon miie.v ture; and. distilli'ng4 ai fraction; enriched ini 2,2;35-r trimethylbutane from: the treated; hydrocarbon.Y mixturer the remaining hydrocarbons comprising.' Z-dimethylpentane.

3; inthe manufacture of zgattnmethymutana the steps comprising: reacting; aemethyl aluminum.y halide.: Witlr alkyl halide in. solutionV in: :an: a/lkane corresponding to. the` alkyl radical ofi said. alkyl: halide such that.. a branched` chain hydrocarbon product comprising 2,2.',3-tri`methylbutane and: Z-Afdimethylpentane is.t obtained,y treating said-l' producirl with. sulfuric acid at. a temperature the: range about 70:: to'. 1525. F2. for' aiperi'od: of. time.l less than about'l 3b hours; such. that Zyl-dimethylLA pentane undergoes substantial; conversion: into-A 2,3'dimethylpentane while 2,2,B-trimethy-llJu-tan'e remains substantially unchanged-f, removing' acidffrom the treated? hydrocarbon mixture, and dis-l tillingi a. traction enriched in 2=,2\;3ftrimetliylbul tane from'. theV treated` hydrocarbon mixture', the remaining hydrocarbons; comprising. 2,3i-diimethylpentane';

41:. In; the manu-i'acture1'y of 2,2,3 -triinet'hylbutane; the. steps; comprising reacting a methyl atlumi` num halide with alkyl halide in solution iwan-'aalekan'ef. corresponding. to thek alkyl-radical'. oi said alkyl halide at a temperature in the range about minus 58 to 32 F. such that a branched chain hydrocarbon product comprising 2,2,3-trimethylbutane and 2,4-dimethylpentane is obtained, treating said product with sulfuric acid at a temperature in the range about 70 to 125 F. for a period of time less than about 3 hours, such that 2,4-dimethy1pentane undergoes substantial conversion into 2,3-dimethylpentane While 2,2,3-trimethylbutane remains substantially unchanged, removing acid from the treated hydrocarbon mixture, and distilling a fraction enriched in 2,2,3- trimethylbutane from the treated hydrocarbon mixture, the remaining hydrocarbons comprising 2,3-dimethylpentane.

5. In the manufacture of 2,2,3-trimethylbutane, the steps comprising reacting methyl alumit 6 num chloride with 2chloro2,3dimethylbutane in solution in 2,3-dimethylbutane at a temperature in the range about minus 58 to 32 F. such that a. branched chain hydrocarbon product comprising 2,2,3-trimethy1butane and 2,4-dimethylpentane is obtained, treating said product with sulfuric acid at a temperature in the range about '70 to 125 F. for a period of time less than about 3 hours such that 2,4-dimethy1pentane undergoes substantial conversion into 2,3-dimethylpentane while 2,2,3-trimethy1butane remains substantially unchanged, removing acid from the treated hydrocarbon mixture, and distilling a fraction enriched in 2,2,3-trim`ethy1butane from the treated hydrocarbon mixture, the remaining hydrocarbons comprising 2,3-dimethy1pentane.

ROBEERT THOMAS SANDERSON. 

